Before starting this campaign I tweaked China modifiers and events to make China dynamic. The challenge was making low mandate and such penalties bad enough for Ming to suffer, but also making it possible for AI minor to take the mandate and not instantly fall over. Vanilla fails both ways - Ming is ridicilously stable, but if by some miracle it collapses (usually involving Unguarded Nomadic Frontier, or player's actions), it's impossible for any new mandate holder to survive.
I ran a few AI games, and I've seen mixed outcomes, once even emergent Wu managing to get over 600dev of China, so I thought it was ready. Unfortunately it was a small sample, and I didn't consider that unlimited idea groups helped Ming a lot by helping every country against rebels - taking Humanist, Religious, or Quantity.
Oh well, I'll skip the whole unifying China from total chaos thing, and just grab the mandate.
I bribed Manchus with 1000 gold, and attacked Ming with Majapahit, Brunei, Manchus, and somehow Mamluks joining me. Mamluks did some colonizing nearby, but that's still surprising. Japan did not join as they liked Ming too much.
In this grand war 282k troops and 57 heavies on attacker side, versus 134k shitty troops and 16 heavies on defender side of Ming and somehow Tonkin.
Naval combat was not going great, so I started fresh ship building program while I invaded from the South. Ming sensibly prioritized kicking the Manchus out of the war first, which it did, even taking two provinces, but it was money well spent.
Actually why do I even bother, I have no reason to transport my troops all over, I can recruit 60k mercs in a few weeks, with two more such stacks as needed.
Surprisingly Mamluks and Brunei very actively participated in the war as well. Mamluks took Nanjing and Beijing, and were really stars of this whole war. Mamluks also had the most ideas (55) of any country, me being second (54), with average country only having about half as much (~27), barely more than they would in vanilla.
As a result, Ming got wrecked, I took mandate and 2 of its capitals, and from then on, nothing bad ever happened to the new Celestial Empire.
So for some conclusions:
- Inti and other New World religions are basically bugged, and only semi-playable
- due to the way rebels and mercs work, it's really hard to mod anyone to have trouble with rebels
- unlimited idea groups is reasonably balanced as all countries can get them
- unlimited idea groups make rebels even weaker than they already are, as so many idea groups (Religious, Humanist, Quantity) wreck rebels; 1.30 rebels are already by far the weakest they've ever been, possibly in any Europa Universalis game
- I really enjoyed playing with straits removed - navies finally mattered like never before
- my China rebalance didn't go far enough as just one extra idea group undid all that work
- I used Support Rebels once against Aragon, and they got crushed in a few seconds - my huge espionage buff did basically nothing, I guess I could go even further
- extra building slots are fine. Honestly I don't see why the game should even bother with building slots.
